Aimpoint ACRO P-1
This compact Red Dot Sight (RDS) is fully enclosed which means that the red LED that projects the sight picture is protected from blockage by dirt, mud, dust, or debris. So all you have to do is keep the front and rear glass clear to aim. If it were unenclosed, something could block the LED and require involved cleaning.
Battery life is about 1.5 years at typical daylight usage settings and much longer at lower settings including NVD. There are 10 display illumination settings changed via the +/- buttons on the side. The ACRO is also rated to 82ft underwater.
It is 1.9″ long x 1.2″ tall x 1.2″ wide and weighs 2.1 oz. Street prices range from under $600 to over $700 depending on the exact kit.
Visit aimpoint.com for full specs, more pictures and videos.